Folding machine



May 2, 19651 M. E. ZIMMERER 2,982,073

FOLDING MACHINE Filed June 25,, 1958 4 Sheets-Sheet 1 INVENTOR. MFR/4 E- Z/MMERER TATTO RN EYS y 1961 M. E. ZIMMERER 2,982,073

FOLDING MACHINE Filed June 23, 1958 4 Sheets-Sheet 2 g INVENTOR.

ATTO RN EYS MARK E. Z/MMEKEIQ I May 2, 1 1 M. E. ZIMMERER 2,982,073

FOLDING MACHINE Filed June 25, 1958 4 Sheets-Sheet 3 INVENTOR. MARK E. Z/MMERE Q ATTORNE y 11961 M. E. ZIMMERER 2,982,073

FOLDING MACHINE Filed June 25,, 1958 4 Sheets-Sheet 4 'IIIIIIIIIIIIIIIIIIIIIIII SEQ/5O INVENTOR.

ATTO R NEYS MHZ 4 E. Z IMMEZ K FOLDING MACHINE Mark E. Zimmerer, Kokomo, Ind., assignor to Kingston Products Corporation, Kokomo, Ind., a corporation of Indiana Filed June 23, 1958, Ser. No. 743,731

11 Claims. (Cl. 53366) This invention relates generally to folding machines, and more specifically to an improved machine for securing a first rigid thermoplastic flange of a carton about a second rigid carton flange.

Although the principles of the present invention may be included invarious folding machines or devices, a particularly useful application is made in a machine which has been adapted to close a thermoplastic egg carton which comprises two separable halves, at least one of which is thermoplastic.

The present invention contemplates the utilization of a means for heating a portion of the thermoplastic to a softening temperature, a means for folding the softened portion about the adjacent part of the carton, together with means for continually moving or translating the carton successively past each of said means.

Accordingly, it is an object of the present invention to provide an improved folding machine, which is adapted to fold rigid thermoplastic by first heating it.

Another object of the present invention is to provide a machine for folding heated thermoplastic wherein the folded portion is held by the machine in a particular manner untilthe thermoplastic has cooled sufficiently to rigidify.

Yet another object of the present invention is to provide a machine which may be employed to close thermoplastic cartons.

Many other advantages, features and additional objects of the present invention will become manifest to those versed in the art upon making reference to the detailed description and the accompanying sheets of drawings in which a preferred structural embodiment incorporating the principles of the present invention is shown by way of illustrative example.

On the drawings: 7

Figure 1 is a side elevational view of a folding machine provided in accordance with the principles of the present invention;

Figure 2 is an enlarged elevational view of the right hand portion of Figure l;

Figure 3 is an enlarged elevational view of the left hand portion of Figure 1;

Figure 4 is a view generally similar to Figure 1, but wherein the supporting elements have been omitted;

Figure 5 in an enlarged view, partly in section, partly in elevation, and partly broken away, of a detail of Figure l; e

Figure 6 is a fragmentary sectional view taken along line VI-VI of Figure 1 showing an egg carton in the machine;

- Figure 7 is a sectional view taken along line VlTVII of Figure 1 and showing an egg carton in the machine; and

Figure 8 is a diagrammatic view in perspective of the drive mechanism of Figure 1.

As shown on the drawings:

'The principles of this invention are particularly usenited States Patent ice ful when embodied in a folding machine assembly such as illustrated in Figure 1, generally indicated by the numeral 10. The folding machine assembly 10 includes a straight heating bar 11, a stationary folding element 12, a pair of driven conveyor belts 13, 14, a series of rolls generally indicated at 15, a common drive means enerally as indicated at 16, and a pair of rigid back-up members 17 and 18 for the belts 13 and 14 respectively. It will be appreciated that when the machine is used to close the carton at two points, several of these elements may be duplicated to eliect simultaneous closing thereof.

The various components of the machine 10 are directly or indirectly supported by a rigid stationary frame 20. The frame 20 includes a series of legs 21, the instant embodiment having six such legs arranged in pairs and disposed on the outer sides of the frame 20. Intermediate the rows of legs, there is disposed an upper bridge work 22 and a lower bridge work 23, each of which is secured to the various legs as by welding. Each of the upper bridge work 22 and the lower bridge work 23'comprises a suitable number of pieces of channel iron suitably welded together to provide means for attaching the various elements and to provide the necessary strength and rigidity for the machine 10. The individual legs 21 in this embodiment are shown as being supported on the top of a bench or table 24. It is to be understood that various brackets or adapters may be provided and secured to the frame 20 and to the various elements of the machine.

The instant machine is provided with two of the heating bars '11, which are best seen in Figures 2 and 6. The instant bars 11 are about 34 inches in length and comprise cold rolled steel having an original diameter of 1% inches. Each of the bars is provided with one or more heating elements 25 which are removably carried within each of the bars 11. The heating elements 25 are connected in series van'th a thermostatic control shown schematically at 26, which control has a knob 27 by which the operating temperature may be selected. The details of the thermostat do not form a part of the instant invention.

Immediately adjacent to the inner end of the heating bar 11, there is disposed the stationary folding element 12. The folding element 12 has a first end 28 and a second end 29. Intermediate these ends, there is a central region 30 which has a contoured surface which is blended with the ends 28 and 29. In this embodiment, the end 28 is generally blended with a flat surface 31 on each of the heating bars "11, the central regions contoured surface makes a twist of approximately degrees, and whereby the second end 29 presents a generally horizontal surface.

The conveyor belt 13 is rotatably supported on the upper bridge work 22. To this end, there is provided a stationary axis pulley 31b which is rotatably supported at the entrance end of the machine 10. There is also provided an adjustable axis pulley 32 disposed at the opposite or discharge end of the machine 10. The belt 13 is also provided with a pair of spring loaded pulleys 33 and 34 which serve to keep the belt taut at all times.

The conveyor belt 14 is supported by a stationary axis pulley 35 and an adjustable axis pulley 36 in downwardly spaced position immediately beneath the belt 13. The adjustments 37 for the pulley 36 may be used to achieve the proper tension on the belt 14, and may also be used as a compensator for various lengths of belt which may be provided. The pulleys 35 and 36 are thus bearingly 0 supported by the lower bridge work 23 of the frame 20.

The upper run of the belt 14 is underlaid by the rigid back-up member 18 so that it cannot sag along the length thereof. The upper run of the belt 13 is likewise underlaid'by a support member 38 which is generally similar to the back-up member 18. The support member 38 extends beneath the upper run of the belt 13 and outwardly along the edges thereof to define a channel which serves to prevent excessive movement of the belt 13 in a lateral direction. While the spring loaded pulleys 33 and 34 provide a constant tension for the belt 13, it can be seen that the adjusting mechanism 39 of the variable position pulley 32 not only allows for the various lengths of belt 13 which may be employed, but, since the belt 13 is generally inelastic, the adjustment 39 also serves to control or select the spacing intermediate the lower run of the belt 13 and the upper run of the belt 14.

As best seen in Figures 3 and 7, the series of rolls 15 includes both spring biased rolls such as 40, driven rolls such as 41, and rolls such as 61 which are neither spring biased nor driven. Each of the rolls is disposed adjacent to another roll, with their axes aligned and with the peripheries of the rolls in generally tangent or neartangent arrangement. Figure 3 shows the rolls which are provided for the instant embodiment on one side of the machine. It is to be understood that a duplicate set of rolls is provided on the opposite side of the machine as shown in Figure 7.

The first pair of rolls is disposed adjacent to the second end 29 of the folding element 12. This pair of rolls has been indicated by the numeral 43. In this embodiment, three such pairs of rolls are successively provided. At least the first pair is disposed so close to the folding element 12 that the rolls thereof may engage softened portions of the carton before such portions have rigidified. In order to insure not only mere engagement but a substantial forming or intimate engagement between the portions of the carton, at least one of the rolls is movably supported, such as the roll 40, and its movable support in turn is biased by a pair of springs 44 which urge the roll 46 positively toward the roll 41. The free spacing between the rolls 40 and 41 is less than the thickness of that portion of the carton which is to pass therethrough so that the spring forces act indirectly on the carton itself. To insure that the carton does not slip with respect to the belts 13 and 14 when it is to pass between a pair of spring biased rolls, means are provided for positively rotatably driving at least one of the rolls, such as the roll 41. To this end, a sprocket wheel 45 has been supplied externally of the supporting bracket 46.

The lower bridge work 23 supports a plate 60 on each side thereof to which is rotatably attached aligned spaced pairs of rolls 61. Each of the rolls 61 is rotatably mounted in a conventional manner, a given pair of rolls having a gap therebetween which is substantially the same size as is the thickness of the carton portion as it leaves the last of the spring biased rolls 40. To the extent that any portion of the carton begins to expand or move away from another portion, the rolls 61 serve to preclude such expansion, to restore the flange position, and to hold it in intimate contact with the other flange portion until the thermoplastic of the carton has cooled sufliciently to again become rigid. It will be noted that the rolls 61 are neither directly driven, except by the carton, nor are they biased toward one another. Rather they are disposed in fixed axial relation to each other. It will be appreciated that the number of rolls 61 and the extent of their distribution may be increased or decreased depending upon the speed at which the belts 13 and 14 are moved so as to provide means for holding the overlying portions of the softened flange for whatever duration of time is necessary to insure that complete rigidification has occurred before the flange is released from the rolls.

The common drive means 16 includes a motor 47 adapted as by a pulley 48 and a belt 49 to rotate the input pulley 50 of a speed reducing gear box 51 which has a plurality of output pulleys 52, 53, and 54. The output pulleys 52 and 53 are each connected as by a link chain 55 to a plurality of drive sprockets 45, each of which is drivably associated with a driven roll 41. The output pulley 54 of the speed reducer 51 is connected as by a link chain '56 to a pair of sprocket drive wheels 31a, 35a respectively drivably associated with the conveyor belt pulleys 31b and 35. An adjustably disposed idler 57 supported by the upper bridge work 22 may be utilized to both take up the slack in the chain 56, and to insure that the chain 56 engages the sprocket wheel 31a for a suflicient peripheral extent. An idler 58 may likewise be supported against the chain 55 to keep it taut. Suitable brackets are provided for the motor 47 and the gear box 51 to rigidly support them to the frame 20.

The rigid back-up member 18 disposed beneath the upper run of the conveyor belt 14 is provided with guide portions 18a best seen in Figure 6. The guide portions 18a extend along the spaced opposite edges of the backup member 18. The guide portions 18a extend in a surrounding fashion about the upper run of the belt 14 so as to preclude lateral movement of the belt 14. In the instant embodiment, the portions 18a extend somewhat further than the distance needed for the belt-guiding function so that they also serve to guide the carton C against lateral movement as it passes through the machine 10. The portions 18a serve a further function. As will be presently explained, there is downward force on the top of the carton C. The material from which the carton is made, while it is rigid, is resiliently yieldable, whereby such force tends to cause bulging or spreading of at least the lower portion of the carton C. The portions 18a thus closely embrace the lower portion of the carton to also back it up to preclude such spreading or bulging.

The back-up member 17, as best seen in Figure 5, includes a rigid metal plate 62 which extends lengthwise of the machine 10 to back up the lower run of the belt 13 adjacent to the heating bar 11 and the series of rolls 15. To allow for minute differences in height of carton passing through the machine, the spring biased pulleys 33 and 34 are capable of yielding against the force of their springs, should the need arise. Likewise, the plate 62 of the back-up member 17 is yieldably mounted so that it too may yield should the need arise. Likewise, it will also yield and follow the lower run of the belt 13 in response to adjustments made at the movable pulley 32. To this end, in this embodiment, there is provided a pair of guide pins 63, 64 which are threadably secured to the plate 62 and which extend upwardly through apertures in the upper bridge work 22. This type of attachment permits the plate 62 to move up and down as required, while any substantial movement in a plane parallel to the lower run of the belt 13 is precluded. Preferably, the pins 63, 64 comprise headed bolts so that when the belt 13 is removed for maintenance or replacement, the plate 62 is supported. Since the belt 13 moves in the direction of the arrows, there is a tendency for the pins 63, 64 to be drawn against the edge of the aperture which is closest to the discharge end of the machine. When so drawn, a certain amount of friction may develop between the pin 63 and the edge of the hole. To avoid this type of rubbing, one end 62a of the plate 62 is upwardly or angularly directed to define an abutment. A screw 65 is adjustably carried by a portion of the frame 20, and may be so positioned that when the belt 13 draws the plate 62 with it to engage the abutment 62a against the screw 65, the pins 63, 64 are substantially centered in their apertures.

The weight of the plate 62 serves to hold the belt 13 against the upper or adjacent surface of the carton. In the instant embodiment, a pair of annular weights 66, 66 have been disposed respectively about each of the pins 63 and 64 to augment the weight of the plate 62.

cartons passing through the machine may thereby be provided with suitable indicia, such as date code, trademarks, or other identification.

While the operation of the instant machine has been disclosed in conjunction with a certain egg carton, it is to be understood that the machine may be used to advantage with other cartons as well.

base 71 comprising polystyrene. Polystyrene has the property that it is rigid at ordinary temperatures, but when its temperature is raised sufliciently, it becomes soft and pliable, its rigidity being reassumed upon cooling.

Accordingly, for this material, the thermostat 26 is set to maintain a temperature at the heating bars in the range of 290-310 F. The base 71 has .a flange including longitudinal portions 72, 73 and a narrow elongated intermediate portion 74. The cover 70 or upper portion of the carton C is likewise also provided with p a rigid flange 75.

When the lower portion of the carton C has been filled and its upper portion disposed above it, the carton is ready to be closed. In this condition, the filled carton is fed into the entranceend of the machine on the belt 14 and is moved by the belt between the guide portions 18a so that the narrow elongated intermediate portions 74 engage the flat heated surfaces 31 of the heater bars 11. Thus heat isdirectly transferred to the portion 74 whereby it becomes softened. As the belts 13 and 14 continue to advance the carton C,. the flange portions 73 engage the end 28 of the folding ele ment 12 and then engage the contoured surface of the central region 30 whereby the portion becomes folded about a portion of the flange 75 of the cover. As best seen in Figure 7, the portions 73 and 72 thereby sandwich in the portion 75, in that the portions 72 and 73 overlie one another.

The end 29 of the folding element 12 completes the folding of the flange 73 and holds it in intimate contact with the adjacent surface of the other flange 75. The end 29 also directs the flanges to be received between the pairs of driven rolls 43 which cooperate to engage the overlying portions to further hold them in intimate contact during'cooling and n'gidifying of the softened flange.

The temperature of the softened flange, in this example, is somewhat less than the temperatures of the heater bar as it leaves the heater bar, and is typically less than 100 F. when it emerges from the last of the non-driven non-biased rolls 61. a

It is to be understood that if heat were provided to the'carton by a means separate from the machine 10, the remainder of the machine could be used to advantage to close the carton.

. While the temperatures and materials given herein are intended to be illustrative, it is to be understood that the portion of the carton to be softened must be heated to a temperature above the lowest softening temperature, and should not be heated to a temperature as high as the lowest burning temperature. The joint thus formed relies on its configuration, rather than on a surface-try surface fusion of the flanges. The resultant joint thereby may be freely disengaged for access to the contents by merely compressing the sidewalls of the cover 70 together so as to permit the withdrawal of the flange 75 from the U-shaped heat-formed flange of the base 71. Likewise, reengagement may be obtained by deflection of the cover 70. i

Although various minor modifications might be sug- 6 gested by those versed in the art, it should beunderstood that I wish to embody within the scope of the patent warranted hereon all such embodiments as reasonably and properly come within the scope of my contribution to the art. I claim as my invention:

1. A machine for securing a first rigid thermoplastic flange of a carton about a second rigid carton flange,

1 comprising in combination: a heating bar adapted to The instant carton includes a cover 70 comprising cellulose acetate, and a engage and to directly heat a narrow elongated intermediate portion of the first flange to a softening temperature; means for folding a portion of the softened first flange to sandwich ,in the second flange intermediate resulting adjacently overlying portions of the first flange; means for holding the overlying portions of the first flange in intimate contact with the second flange during the cooling and rigidifying of the first flange; and means for continually moving the carton successively past each of said means.

2 A machine for securing a first rigid thermoplastic flange of a carton about a second rigid carton flange, said flanges being spaced from and being disposed between the top and the bottom of the carton, comprising in combination: means for directly heating a narrow elongated intermediate portion of the first flange to a softening temperature; means for folding a portion of the softened first flange to sandwich in the second flange intermediate resulting adjacently overlying portions of the first flange; means for holding the overlying portions of the first flange in intimate contact with the second flange during the cooling and rigidifying of the first flange; and driven means adapted to engage the top and the bottom of the carton for continually moving the carton successively past each of said means.

3. A machine for securing a first rigid thermoplastic flange of a carton about a second rigid carton flange, comprising in combination: means for heating the first flange to a softening temperature; means for folding a portion of the softenend first flange to sandwich in the second flange intermediate resulting adjacently overlying portions of the first flange; means for holding theoverlying portions of the first flange in intimate contact with the second flange during the cooling and rigidifying of the first flange; a pair of flexible conveyor belts arranged being yieldably mounted and biased toward the other member. I

4. A machine for securing a first rigid thermoplastic flange of a carton about a second rigid carton flange, comprising in combination: means for heating the first flange to a softening temperature; a stationary element having a first end arranged to engage the softened first flange, a central region having a contoured surface blended with said first end to fold a portion of. the softened first flange about the second flange, and a second oppositely disposed end having a surface blended with said contoured surface for holding .the folded portion against. the second flange during initial cooling; and movably driven means adapted to engage opposite sides of the carton for continually moving the carton successively past said heating means and said stationary element.

5. A machine for securing a first rigid thermoplastic flange of a carton about a second rigid carton flange, comprising in combination: means for heating the first flange to a softening temperature; a stationary element having a first end arranged to engage the softened first flange, and a central region having a contoured surface blended with said first end to fold a portion of the softened first flange about the second flange; means for hold ing the overlying portions of the first flange in intimate contact with the second flange during the cooling and rigidifying of the first flange, said means including a second oppositely disposed end on said stationary ele: ment, said. second end having a surface blended with said contoured surface, and a series of adjacently arranged paired rolls engageable with the overlying portions of the first flange; and movably driven means adapted to engage opposite sides of the carton for continually moving the carton successively past said heating means and said stationary element. 7

6. A machine for securing a first rigid thermoplastic flange of a carton about a second rigid carton flange, comprising in combination: means for heating the first flange to a softening temperature, means for folding a portion of the softenedfirst flange to sandwich in the second flange intermediate resulting adjacently overlying portions of the first flange; means for holding the overlying portions of the first flange in intimate contact with the second flange during the cooling and rigidifying of the first flange, said means including a series of adjacently arranged paired rolls engageable with the overlying portions of the first flange; and driven means adapted to engage opposite sides of the carton for continually moving the carton successively past each of said means.

7. A machine for securing a first rigid thermoplastic flange of a carton about a second rigid carton flange, comprising in combination: means for heating the first flange to a softening temperature; means for folding a portion of the softened first flange to sandwich in the second flange intermediate resulting adjacently overlying portions of the first flange; means for holding the overlying portions of the first flange in intimate contact with the second flange during the cooling and rigidifying of the first flange, said means including a series of adjacently arranged paired rolls engageable with the overlying portions of the first flange, at least one of said pairs of rolls being disposed adjacent to said folding means and having means for positively biasing said rolls against the overlying portions before they have rigidified; and driven means adapted to engage opposite sides of the carton for continually moving the carton successively past each of said means.

8. A machine for securing a first rigid thermoplastic flange of a carton about a second rigid carton flange, comprising in combination: means for heating the first flange to a softening temperature; means for folding a portion of the softened first flange to sandwich in the second flange intermediate resulting adjacently overlying portions of-the first flange; and a series of cooperatively arranged pairs of rolls engageable with at least one-of said flanges, at least one of said rolls being rotatably driven for continually applying a moving force to cartons engaged thereby.

9. A machine for securing a first rigid thermoplastic flange of a carton about a second rigid carton flange, comprising in combination: means for heating the first flange to a softening temperature; means for folding a portion of the softened first flange to sandwich in the second flange intermediate resulting adjacently overlying portions of the first flange; a pair of driven conveyor belts arranged to engage opposite sides of the carton respectively, for continually moving the carton successively past each of said means; a pair of cooperatively arranged rolls engageable with at least one of said flanges, at least one of said rolls being rotatably driven for aiding said continual movement; and common drive means for simultaneously'driving each of said driven belts and said driven roll.

10. A machine for securing a first rigid thermoplastic flange of a carton about a second rigid carton flange, comprising in combination: means for heating the first flange to a softening temperature;-means for folding a portion of the softened first flange to sandwich in the second. flange intermediate resulting adjacently overlying portions of the first flange; means for holding the overlying portions of the first flange 'in intimate contact with the second flange during the cooling and rigidifying of the first flange; a pair of flexible conveyor belts arranged to engage opposite sides of the carton respectively, for continually moving the carton successively past each of said means; and a back-up member for one of said belts.

and disposed to oppose movement of said one belt in a direction away from the other belt, said member having guide portions along spaced edges thereof and extending beyond said one belt to at least partially embrace the edges of the carton to hold it on said one belt.

IL A machine for securing a first rigid thermoplastic flange of a carton about a second rigid carton flange, comprising in combination: a heating bar adapted to engage, and to directly heat a narrow elongated intermediate portion of the first flange to a softening temperature, said bar being adapted to be continually maintained at a temperature intermediate the lowest softening and the lowest burning temperatures of the flange; a stationary element having a first end arranged to engage the softened first flange, a central region having a contoured surface blended with said first end to fold a portion of the softened first flange about the second flange, and a second oppositely disposed end having an surface blended with said contoured surface for holding the folded portion against the secondflange during cooling; a pair of driven conveyor belts arranged to engage opposite sides of the carton respectively, for continually moving the carton successively past each of said heating bar and folding element; a series of adjacently arranged paired rolls engageable with the overlying portions of the first flange at least one of said pairs of rolls being disposed adjacent to said second end of said folding element and having means for positively biasing said rolls against the overlying portions before they have rigidified, at least one of said rolls being rotatably driven for aiding said continual movement; common drive means for simultaneously driving each of said driven belts and said driven roll; and a rigid back-up member for each of said belts and each respectively disposed to oppose movement of said belt in a direction away from the carton, one of said members being yieldably mounted in biased relation toward the other member against one belt, and said other member having guide portions along spaced edges thereof and extending beyond the other belt to at least partially embrace the edges of the carton to hold it on said other belt.

References Cited in the file of this patent UNITED STATES PATENTS 2,202,006 Hothersall May 28, 1940 2,284,833 Mirando et al. June 2, 1942 2,451,273 Bright Oct. 12, 1948 2,559,365 Middleton et al July 3, 1951 2,669,740 Main Feb. 23, 1954 2,669,815 Zinn et a1 Feb. 23, 1954 2,853,118 Schnitzius Sept. 23, 1958 

